Variation of light emitting properties of ZnO thin films depending on post-annealing temperature

ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition (PLD). In order to investigate the effect of post-annealing treatment on the optical property of ZnO thin films, films have been annealed in oxygen at various annealing temperatures after deposition. After post-annealing treatment in the oxygen ambient, the optical properties of ZnO thin films were characterized by photoluminescence (PL). The structural properties of ZnO thin films were characterized by XRD. Crystallinity of ZnO film is enhanced at annealing temperature above 700 °C. As the post-annealing temperature increases, intensity of UV (380 nm) peak is decreased while the intensity of visible (about 490–530 nm) peak is increased, carrier concentration is decreased and resistivity was increased. Structural, electrical and optical properties of ZnO films have been investigated for the application of light emission device.